1. Technical Field
The disclosure relates to a charged particle beam apparatus which moves a sample piece processed by means of a charged particle beam to another sample holder, and a sample observation method.
2. Description of the Related Art
A transmission electron microscope (TEM) observation is known as a method of observing a fine area in a sample so as to perform a defect analysis of a semiconductor device. The TEM observation requires manufacture of a TEM sample having a thin film in which an electron beam can be transmitted to a portion of the sample as preparation of the sample for obtaining a transmission electron image. In recent years, as a method of manufacturing the TEM sample, a TEM sample manufacturing method by means of a focused ion beam (FIB) has been widely used. In this method, when a structure such as the semiconductor device is exposed to an observation surface of a thin sample piece, a phenomenon of a line in which an unevenness is formed on the observation surface, a so-called curtaining effect may occur since etching rates of the focused ion beams are different from each other depending on the existence of the structure. For this reason, there has been a problem in that a line is formed on an observation image of the observation surface through an ion beam process in addition to the line caused by a device structure in the related art.
As a solution to this problem, a method has been proposed, in which a sample piece which is cut off from a wafer on a sample stage is rotated by a probe and then fixed to a TEM sample holder on the sample stage (refer to JP-A-2009-110745). According to this method, the sample piece which is fixed to the TEM sample holder can allow a structure to be disposed on the side of a holder and even though the sample piece is irradiated with the ion beam, there is no structure on an incident side, thereby reducing an influence of a curtaining effect.
Meanwhile, an FIB-SEM composite device has been known as a device for observing a cross section, which is etched by irradiating the sample piece with the focused ion beam, by using a scanning electron microscope (SEM). Generally, an SEM observation can be performed with a high resolution when the observation is performed from a direction perpendicular to the observation surface. Thus, a sample processing observation method has been proposed, which performs the SEM observation from a direction perpendicular to a cross section, which is formed through the FIB processing, by using the charged particle beam apparatus in which an FIB column and an SEM column are disposed to be perpendicular to each other (refer to JP-A-2011-196802). According to this method, it is possible to perform the SEM observation for the cross section which is cut off by micromachining by means of the FIB at once with a high resolution.